What is the probability of selecting a red marble followed by a blue marble if you replace the marble in between drawing. a box contains 3 red marbles 6 blue marbles and 1 white marble

Basically, choosing one red marble out of everything is 3 / 10 because there are 3 chances of picking the red marble and 10 marbles overall. Picking one blue marble would be 6 / 10, or 3 / 5. You would multiply these two probabilities together because they are independent of each other:

(3 / 10)*(3 / 5) = 9 / 50

The probability is 9 / 50.

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.